Optical telecommunications networks are growing increasingly complex, developing beyond simple passive transport of signals to dynamic routing of the signals. A main objective of power management in these dynamic networks, for example metropolitan area networks (MANs), is the management of network power levels during adding and dropping of channels, network upgrades and reconfigurations. Several methods of such power monitoring and management in optical networks are currently available.
The U.S. patent application No. 20030053163 to Li et al. dated Mar. 20, 2003 and entitled “Analogous Channel Method for Performance Monitoring and Equalization in Optical Networks”, discloses a method of monitoring and equalizing dense wavelength division multiplexing (DWDM) optical links by adjusting input power. In this method, the input power is adjusted to optimize optical network parameters such as optical signal to noise ratio (OSNR) and bit error rate (BER). This requires the complex and costly monitoring of the optical network parameters.
The U.S. Pat. No. 6,304,347 to Beine et al. issued Oct. 16, 2001 and entitled “Optical Power Management in an Optical Network”, discloses a method of managing power levels in a network by providing the nodes of the network with parameters to configure the node. The input powers to each node are maintained at a constant level by adjustment of the node configuration parameters. Thus, this patent provides management of network power by strictly maintaining constant power levels at specific points in the network, requiring many monitored points and the exchange of information between network components.
The U.S. patent application No. 20030133713 to Ng et al. dated Jul. 17, 2003 and entitled “Method and System for Multi-Level Power Management in an Optical Network”, discloses a method of managing power levels in a network through multi-level control of amplifier gain settings. This patent is concerned only with the effects of amplifiers on variation of signal power levels and does not correct for power variation due to any other effects.
Therefore, there is a need in industry for the development of an improved method for simple yet comprehensive power management in an optical network.